From: Rade Bozic <rade.bozic.ext@xxxxxxx>
Signed-off-by: Rade Bozic <rade.bozic.ext@xxxxxxx>
Signed-off-by: David Daney <ddaney@xxxxxxxxxxxxxxxxxx>
---
drivers/i2c/busses/Kconfig | 10 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-octeon.c | 579 +++++++++++++++++++++++++++++++++++++++
3 files changed, 590 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-octeon.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 5f318ce..737f052 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -564,6 +564,16 @@ config I2C_VERSATILE
This driver can also be built as a module. If so, the module
will be called i2c-versatile.
+config I2C_OCTEON
+ tristate "Cavium OCTEON I2C bus support"
+ depends on CPU_CAVIUM_OCTEON
+ help
+ Say yes if you want to support the I2C serial bus on Cavium
+ OCTEON SOC.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-octeon.
+
comment "External I2C/SMBus adapter drivers"
config I2C_PARPORT
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 302c551..c2c4ea1 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -54,6 +54,7 @@ obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o
obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
obj-$(CONFIG_I2C_STU300) += i2c-stu300.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
+obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
# External I2C/SMBus adapter drivers
obj-$(CONFIG_I2C_PARPORT) += i2c-parport.o
diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
new file mode 100644
index 0000000..57455ac
--- /dev/null
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -0,0 +1,579 @@
+/*
+ * (C) Copyright 2009-2010
+ * Nokia Siemens Networks, michael.lawnick.ext@xxxxxxx
+ *
+ * This is a driver for the i2c adapter in Cavium Networks' OCTEON processors.
+ *
+ * Release 0.1
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+
+#include <linux/io.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+
+#include <asm/octeon/octeon.h>
+
+#define DRV_NAME "i2c-octeon"
+#define DRV_VERSION "0.1"
+
+/* register offsets */
+#define SW_TWSI 0x00
+#define TWSI_INT 0x10
+
+/* Controller command patterns */
+#define SW_TWSI_V 0x8000000000000000ull
+#define SW_TWSI_EOP_TWSI_DATA 0x0C00000100000000ull
+#define SW_TWSI_EOP_TWSI_CTL 0x0C00000200000000ull
+#define SW_TWSI_EOP_TWSI_CLKCTL 0x0C00000300000000ull
+#define SW_TWSI_EOP_TWSI_STAT 0x0C00000300000000ull
+#define SW_TWSI_EOP_TWSI_RST 0x0C00000700000000ull
+#define SW_TWSI_OP_TWSI_CLK 0x0800000000000000ull
+#define SW_TWSI_R 0x0100000000000000ull
+
+/* Controller command and status bits */
+#define TWSI_CTL_CE 0x80
+#define TWSI_CTL_ENAB 0x40
+#define TWSI_CTL_STA 0x20
+#define TWSI_CTL_STP 0x10
+#define TWSI_CTL_IFLG 0x08
+#define TWSI_CTL_AAK 0x04
+
+/* Some status values */
+#define STAT_START 0x08
+#define STAT_RSTART 0x10
+#define STAT_TXADDR_ACK 0x18
+#define STAT_TXDATA_ACK 0x28
+#define STAT_RXADDR_ACK 0x40
+#define STAT_RXDATA_ACK 0x50
+#define STAT_IDLE 0xF8
+
+#ifndef NO_IRQ
+#define NO_IRQ (-1)
+#endif
+
+struct octeon_i2c {
+ wait_queue_head_t queue;
+ struct i2c_adapter adap;
+ int irq;
+ int twsi_freq;
+ int sys_freq;
+ uint8_t twsi_ctl;
+ resource_size_t twsi_phys;
+ void __iomem *twsi_base;
+ resource_size_t regsize;
+ struct device *dev;
+};
+
+/* Writes need to be flushed by a read. */
+static void octeon_i2c_write_sw(struct octeon_i2c *i2c,
+ uint64_t eop_reg,
+ uint8_t data)
+{
+ uint64_t tmp;
+
+ __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI);
+ tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
+}
+
+static uint8_t octeon_i2c_read_sw(struct octeon_i2c *i2c, uint64_t eop_reg)
+{
+ uint64_t tmp;
+
+ __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI);
+ tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
+
+ return __raw_readq(i2c->twsi_base + SW_TWSI) & 0xFF;
+}
+
+static void octeon_i2c_write_int(struct octeon_i2c *i2c, uint64_t data)
+{
+ uint64_t tmp;
+
+ __raw_writeq(data, i2c->twsi_base + TWSI_INT);
+ tmp = __raw_readq(i2c->twsi_base + TWSI_INT);
+}
+
+static void octeon_i2c_int_enable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_write_int(i2c, 0x40);
+}
+
+static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_write_int(i2c, 0);
+}
+
+/* If there was a reset while a device was driving 0 to bus,
+ bus is blocked. We toggle it free manually by some clock
+ cycles and send a stop. */
+static void octeon_i2c_unblock(struct octeon_i2c *i2c)
+{
+ int i;
+
+ dev_dbg(i2c->dev, "%s\n", __func__);
+ for (i = 0; i < 9; i++) {
+ octeon_i2c_write_int(i2c, 0x0);
+ udelay(5);
+ octeon_i2c_write_int(i2c, 0x200);
+ udelay(5);
+ }
+ octeon_i2c_write_int(i2c, 0x300);
+ udelay(5);
+ octeon_i2c_write_int(i2c, 0x100);
+ udelay(5);
+ octeon_i2c_write_int(i2c, 0x0);
+}
+
+static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
+{
+ struct octeon_i2c *i2c = dev_id;
+
+ octeon_i2c_int_disable(i2c);
+ i2c->twsi_ctl = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_CTL);
+ wake_up_interruptible(&i2c->queue);
+
+ return IRQ_HANDLED;
+}
+
+static int octeon_i2c_wait(struct octeon_i2c *i2c)
+{
+ unsigned long orig_jiffies = jiffies;
+ uint8_t ctl;
+ int result = 0;
+
+ if (i2c->irq == NO_IRQ) {
+ /* polling */
+ do {
+ ctl = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_CTL);
+ if (ctl & TWSI_CTL_IFLG)
+ break;
+ } while (!time_after(jiffies,
+ orig_jiffies + i2c->adap.timeout));
+
+ if (!(ctl & TWSI_CTL_IFLG)) {
+ dev_dbg(i2c->dev, "%s: timeout\n", __func__);
+ result = -ETIMEDOUT;
+ }
+ } else {
+ i2c->twsi_ctl = 0;
+ /* interrupt mode */
+ octeon_i2c_int_enable(i2c);
+
+ result = wait_event_interruptible_timeout(i2c->queue,
+ (i2c->twsi_ctl & TWSI_CTL_IFLG),
+ i2c->adap.timeout);
+
+ if (unlikely(result < 0)) {
+ dev_dbg(i2c->dev, "%s: wait interrupted\n", __func__);
+ } else if (unlikely(!(i2c->twsi_ctl & TWSI_CTL_IFLG))) {
+ dev_dbg(i2c->dev, "%s: timeout\n", __func__);
+ result = -ETIMEDOUT;
+ }
+ }
+
+ return result < 0 ? result : 0;
+}
+
+static int octeon_i2c_start(struct octeon_i2c *i2c)
+{
+ uint8_t data;
+ int result;
+
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+ TWSI_CTL_ENAB | TWSI_CTL_STA);
+
+ result = octeon_i2c_wait(i2c);
+ if (unlikely(result < 0) &&
+ octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT) == STAT_IDLE) {
+ /*
+ * Controller refused to send start flag May be a
+ * client is holding SDA low - let's try to free it.
+ */
+ octeon_i2c_unblock(i2c);
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+ TWSI_CTL_ENAB | TWSI_CTL_STA);
+
+ result = octeon_i2c_wait(i2c);
+ if (result < 0)
+ return result;
+ }
+
+ data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+ if ((data != STAT_START) && (data != STAT_RSTART)) {
+ dev_dbg(i2c->dev, "%s: bad status (0x%x)\n", __func__, data);
+ return -1;
+ }
+
+ return 0;
+}
+
+static int octeon_i2c_stop(struct octeon_i2c *i2c)
+{
+ unsigned long orig_jiffies = jiffies;
+ uint8_t data;
+
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+ TWSI_CTL_ENAB | TWSI_CTL_STP);
+
+ /*
+ * Controller will change to idle, but that does not raise an
+ * interrupt, so we have to poll.
+ */
+ do {
+ data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+ if (data == STAT_IDLE)
+ break;
+ udelay(1);
+ } while (!time_after(jiffies, orig_jiffies + 2));
+
+ if (data != STAT_IDLE) {
+ dev_dbg(i2c->dev, "%s: bad status(0x%x)\n", __func__, data);
+ return -1;
+ }
+ return 0;
+}
+
+static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
+ const uint8_t *data, int length)
+{
+ int i, result;
+ uint8_t tmp;
+
+ result = octeon_i2c_start(i2c);
+ if (unlikely(result < 0))
+ return result;
+
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, target << 1);
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+ result = octeon_i2c_wait(i2c);
+ if (unlikely(result < 0))
+ return result;
+
+ for (i = 0; i < length; i++) {
+ tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+ if ((tmp != STAT_TXADDR_ACK) && (tmp != STAT_TXDATA_ACK)) {
+ dev_dbg(i2c->dev,
+ "%s: bad status before write (0x%x)\n",
+ __func__, tmp);
+ return -(int)tmp;
+ }
+
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, data[i]);
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+ result = octeon_i2c_wait(i2c);
+ if (unlikely(result < 0))
+ return result;
+ }
+
+ return 0;
+}
+
+static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
+ uint8_t *data, int length)
+{
+ int i, result;
+ uint8_t tmp;
+
+ if (length < 1)
+ return -EINVAL;
+
+ result = octeon_i2c_start(i2c);
+ if (result)
+ return result;
+
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, (target<<1) | 1);
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+ result = octeon_i2c_wait(i2c);
+ if (unlikely(result < 0))
+ return result;
+
+ for (i = 0; i < length; i++) {
+ tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+ if ((tmp != STAT_RXDATA_ACK) && (tmp != STAT_RXADDR_ACK)) {
+ dev_dbg(i2c->dev,
+ "%s: bad status before read (0x%x)\n",
+ __func__, tmp);
+ return -(int)tmp;
+ }
+
+ if (i+1 < length)
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+ TWSI_CTL_ENAB | TWSI_CTL_AAK);
+ else
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+ TWSI_CTL_ENAB);
+
+ result = octeon_i2c_wait(i2c);
+ if (unlikely(result < 0))
+ return result;
+
+ data[i] = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_DATA);
+ }
+ return length;
+}
+
+static int octeon_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs,
+ int num)
+{
+ struct i2c_msg *pmsg;
+ int i;
+ int ret = 0;
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+ for (i = 0; ret >= 0 && i < num; i++) {
+ pmsg = &msgs[i];
+ dev_dbg(i2c->dev,
+ "%s: Doing %s %d byte(s) to/from 0x%02x - "
+ "%d of %d messages\n",
+ __func__,
+ pmsg->flags & I2C_M_RD ? "read" : "write",
+ pmsg->len, pmsg->addr, i + 1, num);
+ if (pmsg->flags & I2C_M_RD)
+ ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
+ pmsg->len);
+ else
+ ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
+ pmsg->len);
+ }
+ octeon_i2c_stop(i2c);
+
+ return (ret < 0) ? ret : num;
+}
+
+static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm octeon_i2c_algo = {
+ .master_xfer = octeon_i2c_xfer,
+ .functionality = octeon_i2c_functionality,
+};
+
+static struct i2c_adapter octeon_i2c_ops = {
+ .owner = THIS_MODULE,
+ .name = "OCTEON adapter",
+ .algo = &octeon_i2c_algo,
+ .timeout = 2,
+};
+
+static int __init octeon_i2c_setclock(struct octeon_i2c *i2c)
+{
+ int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff;
+ int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = 1000000;
+
+ for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) {
+ /*
+ * An mdiv value of less than 2 seems to not work well
+ * with ds1337 RTCs, so we constrain it to larger
+ * values.
+ */
+ for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) {
+ /*
+ * For given ndiv and mdiv values check the
+ * two closest thp values.
+ */
+ tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10;
+ tclk *= (1 << ndiv_idx);
+ thp_base = (i2c->sys_freq / (tclk * 2)) - 1;
+ for (inc = 0; inc <= 1; inc++) {
+ thp_idx = thp_base + inc;
+ if (thp_idx < 5 || thp_idx > 0xff)
+ continue;
+
+ foscl = i2c->sys_freq / (2 * (thp_idx + 1));
+ foscl = foscl / (1 << ndiv_idx);
+ foscl = foscl / (mdiv_idx + 1) / 10;
+ diff = abs(foscl - i2c->twsi_freq);
+ if (diff < delta_hz) {
+ delta_hz = diff;
+ thp = thp_idx;
+ mdiv = mdiv_idx;
+ ndiv = ndiv_idx;
+ }
+ }
+ }
+ }
+ octeon_i2c_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp);
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
+
+ return 0;
+}
+
+static int __init octeon_i2c_initlowlevel(struct octeon_i2c *i2c)
+{
+ uint8_t status;
+ int tries;
+
+ /* disable high level controller, enable bus access */
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+ /* reset controller */
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_RST, 0);
+
+ for (tries = 10; tries; tries--) {
+ udelay(1);
+ status = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+ if (status == STAT_IDLE)
+ return 0;
+ }
+ dev_dbg(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n", __func__, status);
+ return -1;
+}
+
+static int __init octeon_i2c_probe(struct platform_device *pdev)
+{
+ int irq, result = 0;
+ struct octeon_i2c *i2c;
+ struct octeon_i2c_data *i2c_data;
+ struct resource *res_mem;
+
+ i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
+ if (!i2c) {
+ printk(KERN_ERR "%s i2c-cavium - kzalloc failed\n", __func__);
+ return -ENOMEM;
+ }
+ i2c->dev = &pdev->dev;
+ i2c_data = pdev->dev.platform_data;
+
+ res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ irq = platform_get_irq(pdev, 0);
+
+ if (res_mem == NULL) {
+ dev_dbg(i2c->dev, "%s: found no memory resource\n", __func__);
+ kfree(i2c);
+ return -ENODEV;
+ }
+
+ if (i2c_data == NULL) {
+ dev_dbg(i2c->dev, "%s: no I2C frequence data\n", __func__);
+ kfree(i2c);
+ return -ENODEV;
+ }
+
+ i2c->twsi_phys = res_mem->start;
+ i2c->regsize = resource_size(res_mem);
+ i2c->twsi_freq = i2c_data->i2c_freq;
+ i2c->sys_freq = i2c_data->sys_freq;
+
+ if (!request_mem_region(i2c->twsi_phys, i2c->regsize, res_mem->name)) {
+ dev_dbg(i2c->dev,
+ "%s i2c-cavium - request_mem_region failed\n",
+ __func__);
+ goto fail_region;
+ }
+ i2c->twsi_base = ioremap(i2c->twsi_phys, i2c->regsize);
+
+ init_waitqueue_head(&i2c->queue);
+
+ i2c->irq = irq;
+ if (i2c->irq != NO_IRQ) {
+ /* i2c->irq = NO_IRQ implies polling */
+ result = request_irq(i2c->irq, octeon_i2c_isr, 0, DRV_NAME, i2c);
+ if (result < 0) {
+ dev_dbg(i2c->dev,
+ "%s: - failed to attach interrupt\n",
+ __func__);
+ goto fail_irq;
+ }
+ }
+
+ result = octeon_i2c_initlowlevel(i2c);
+ if (result) {
+ dev_dbg(i2c->dev, "%s: init low level failed\n", __func__);
+ goto fail_add;
+ }
+
+ result = octeon_i2c_setclock(i2c);
+ if (result) {
+ dev_dbg(i2c->dev, "%s: clock init failed\n", __func__);
+ goto fail_add;
+ }
+
+ i2c->adap = octeon_i2c_ops;
+ i2c->adap.dev.parent = &pdev->dev;
+ i2c->adap.nr = pdev->id >= 0 ? pdev->id : 0;
+ i2c_set_adapdata(&i2c->adap, i2c);
+ platform_set_drvdata(pdev, i2c);
+
+ result = i2c_add_numbered_adapter(&i2c->adap);
+ if (result < 0) {
+ dev_dbg(i2c->dev, "%s: failed to add adapter\n", __func__);
+ goto fail_add;
+ }
+ return result;
+
+fail_add:
+ platform_set_drvdata(pdev, NULL);
+ if (i2c->irq != NO_IRQ)
+ free_irq(i2c->irq, i2c);
+fail_irq:
+ iounmap(i2c->twsi_base);
+ release_mem_region(i2c->twsi_phys, i2c->regsize);
+fail_region:
+ kfree(i2c);
+ return result;
+};
+
+static int __exit octeon_i2c_remove(struct platform_device *pdev)
+{
+ struct octeon_i2c *i2c = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&i2c->adap);
+ platform_set_drvdata(pdev, NULL);
+ if (i2c->irq != NO_IRQ)
+ free_irq(i2c->irq, i2c);
+ iounmap(i2c->twsi_base);
+ release_mem_region(i2c->twsi_phys, i2c->regsize);
+ kfree(i2c);
+ return 0;
+};
+
+static struct platform_driver octeon_i2c_driver = {
+ .probe = octeon_i2c_probe,
+ .remove = __exit_p(octeon_i2c_remove),
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = DRV_NAME,
+ },
+};
+
+static int __init octeon_i2c_init(void)
+{
+ int rv;
+
+ rv = platform_driver_register(&octeon_i2c_driver);
+ printk(KERN_INFO "driver %s is loaded\n", DRV_NAME);
+ return rv;
+}
+
+static void __exit octeon_i2c_exit(void)
+{
+ platform_driver_unregister(&octeon_i2c_driver);
+ printk(KERN_INFO "driver %s unloaded\n", DRV_NAME);
+}
+
+MODULE_AUTHOR("Michael Lawnick <michael.lawnick.ext@xxxxxxx>");
+MODULE_DESCRIPTION("I2C-Bus adapter for Cavium OCTEON processors");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+MODULE_ALIAS("platform:" DRV_NAME);
+
+module_init(octeon_i2c_init);
+module_exit(octeon_i2c_exit);
+
--
1.6.0.6
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